Vertical multiple spindle machine

ABSTRACT

In a vertical multiple spindle machine, the outlets of the oil supply passages provided in the stationary column mounting a table capable of revolving about this column and carrying hydraulic clamping means and the oil inlets of the table are disposed at the same level and arranged so that in each fixed position of the table a regular inlet thereof communicates with the same outlet of the passage of the column, while in the process of turning the table from one fixed position to another the inlets of the table alternately and successively communicate with the remaining outlets of the passages of the column.

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[ VERTICAL MULTIPLE SPINDLE MACHBNE [75] Inventors: Artur Khaimovich Agishtein, Moscow, U.S.S.R.

[73] Assignee: Moskovsky Stankostroitelny Zavood, Moscow, U.S.S.R.

[22] Filed: Fuly 28, 1971 [21] Appl. No.: 166,889

Markovich ltin; Ernst both of [52] US. Cl. ..29/38 A, 90/56 R, 408/71 '[51] Int. Cl. ..B23p 23/02 [58] Field of Search ..90/56 R; 29/37 R, 38 A; 408/71, 44

[56] References Cited UNITED STATES PATENTS 3,424,319 1/1969 Hohlfelder, Jr ..90/56 X FOREIGN PATENTS OR APPLICATIONS 497,873 12/ 1938 Great Britain ..29/38.2 445,240 4/1936 Great Britain ..29/38.2

Primary Examiner-Gil Weidenfeld Attorney-Holman & Stern [57] ABSTRACT another the inlets of the table alternately and successively communicate with the remaining outlets of the passages of the column.

2Claims,2Drawing VERTICAL MULTIPLE SPINDLE MACHINE the present invention relates to metal-cutting machines and, more particularly, the invention relates to vertical multiple spindle machines.

The invention can be most successfully used for large-series production of articles, particularly in the automotive and tractor industries.

Known in the art are vertical multiple spindle machines in which the revolving table carrying hydraulic clamping means is mounted with its central aperture on a conical portion of a stationary column.

In these known machines locatedalong the perimeter of the conical portion of the stationary column are openings of passages for feeding oil forced into the receiving channels of the table communicating with the hydraulic clamping means mounted on the revolving table.

The oil is forced continuously, in which case the oil is delivered from the openings of the passages of the column into the receiving channels of the revolving table through a circular groove on the tapered portion of the column. Whenthe oil is forced under a pressure of 29,1740;kgf/crn?v through the circular grooyehaving a diameter'df sub-1,000 mm, considerable leakage of oil occurs through the gap between the conjugated surfaces of the table and column which is required for the provision of free rotation of the table about the column.

This leakage leads to a pressure decrease in the hydraulic clamping means of the table. As a result the clamping effort applied to the blanks is diminished and this results in a low accuracy of workpieces being machined. If the pressure decrease is considerable, this may result in an emergency junping of the blank from the clamping means.

To compensate for these leakages of oil and to provide for normal operation of the hydraulic clamping means mounted on the revolving table, the output capacity of the oil pump and the input power of the electric motor of the hydraulic system of the machine must be of a considerable value.

This is associated with an increased consumption of electric energy, high cost and large dimensions of the auxiliary and control electric and hydraulic equipment.

Furthermore, due to leakage of a large quantity of oil through the gap between the conjugated surfaces of the column and table, there is evolved a high amount of heat, resulting in overheating of the column and table which are basic components of the machine. It is clear that the thermal strains of the basic components of the machine reduce its accuracy. This, in turn, adversely affects the accuracy of the workpieces being processed on the machine. It should be noted that an increased temperature of the oil adversely affects the operation of the hydraulic system of the machine.

Also known in the art are vertical multiple spindle machines of the same type as described above, in which the leakage of oil through the gap between the table and the column is diminished due to the fact that, instead of the circular groove, the conical portion has symmetrically located supply slots communicating with the oil supply passages, while the receiving channels are interconnected by a ring of hoses.

The supply slots communicating with the passages of the column havea considerable length, of the order of one-tenthto one-fifteenth of the perimeter of the conjugated surfaces, because the sum of the lengths of the supply slots must be somewhat greater than the distance between the receiving channels along the conjugated surfaces of the table and column. Hence, the above-mentioned construction contributes to reduction of the oil leakage over the conjugated surfaces of the table and column, yet in this case, too, the leakage is considerable.

Furthermore, formed about the long supply slots in the gap between the conjugated surfaces of the table and column there are so-called oil spots, i.e., portions filled with oil under a pressure of 40 kgf/cm. This causes complex deformations of the table and its misalignment relative to the stationary column.

As a result, the accuracy of themachine is deteriorated, while greater efforts are needed for turning the table about the column.

An object of the present invention is to eliminate the above-mentioned disadvantages.

Another object of the invention is to provide a vertical multiple spindle machine having such a mutual disposition of the outlets of the oil supply passages and the inlets of the revolving table that the leakage of oil through the gap between the conjugated surfaces of the column and table is minimized.

Still another object of the invention is to provide a machine of the above type in which a stable position of the revolving table relative to the stationary column is constantly maintained.

Yet another object of the invention is to provide such a system of a multiple spindle machine which will ensure high accuracy of workpieces being machined.

These and other object are attained through a proposed vertical multiple spindle machine, in which the revolving table carrying the hydraulic clamping means is mounted with its central aperture on the tapered portion of a stationary column having along its perimeter outlets of supply passages for oil forced under pressure into the inlets of the table disposed at the level of said outlets and interconnected through an annular channel, which inlets communicate respectively with the hydraulic devices. According to the invention, the outlets of the passages of the column and the inlets of the table, which are positioned at the same level, are located so that in each fixed position of the table its regular inlet communicates with the same outlet of the passage of the column, while in the process of revolving the table from one fixed position to another its inlets alternately and successively communicate with the remaining outlets of the passages.

The inlets of the table are preferably disposed at an equal angular pitch relative to each other along the perimeter of the conjugated surface of the tapered portion while the outlets of the passages are preferably spaced through an unequal angular pitch so that, when the outlet of one passage coincides with the inlet of the table, the outlets of the other passages of the column are displaced with respect to the adjacent inlets in the direction of rotation of the table through constant angles the magnitudes of which are not equal and constitute a progression.

Due to such a layout of the outlets of the passages of the stationary column and the inlets of the table in the proposed machine the leakage of oil through the gap between the conjugated surfaces of the table and column is minimized, thus providing for a stable position of the table relative to the column, which, in turn,

provides for high accuracy of the workpieces on this machine.

The present invention will be further described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a front view, partly in section, of the vertical multiple spindle machine according to the invention;

FIG. 2 is a diagram of mutual layout of the outlets of the passages of the column and the inlets of the table according to the invention.

The proposed vertical multiple spindle machine has a revolving table 1 (FIG.'1) carrying hydraulic means A for clamping the workpieces to be machined. The table with its central aperture is mounted on the conical portion B of a stationary column 2. The tapered portion has along its perimeter outlets 3 of passages 4 feeding oil which is forced into the inlets of the table disposed at. the same level as said outlets 3. The inlets 5 correspondingly communicate with the above-said hydraulic clampingmeans. I I

According to the invention, the outlets 3 of the passages 4 of the column 2 and the inlets 5 are laid out at the same level and are arranged so that in each fixed position of the table 1 a regular inlet 5a (FIG. 2) of the table communicates with the same outlet 3a of the passage, while in the process of revolving the table inthe direction of the arrow C from one fixed position to another its inlets 5b through 5h alternately and, successively communicate with the remaining outlets 3b, 3c, 3d of the passages 4.

In the embodiment of the invention under consideration the inlets 5a through 5h of the table 1 along the perimeter of the surface of the column 2 conjugated with the tapered portion B of the column are arranged at an equal angular pitch relative to-each other. This pitch is equal to 360/n, where n. is the number of fixed positions of the table. Described herein is a vertical eight-spindle machine with eight fixed positions of the table. Therefore, the angle between the inlets of the table is equal to 360/8 45. The angle of rotation of the table from one fixed position to another is also equal to 360/8 =45.

The outlets 3 of the passages of the column are spaced through an unequal angular pitch so that at a coincidence of the outlet 3a of one passage 4 with the inlet 5a of the table 1 the outlets 3b, 3c, 3d of the remaining passages are displaced relative to the adjacent inlets 5b, 5d, 5f of the table in the direction of its rotation indicated by the arrow C through constant angles a a a the magnitudes of which are not equal and constitute a progression.

Since the angle of rotation of the table from one fixed position to another is equal to 45, and the column has four outlets 3a, 3b, 3c and 3d of the oil supply passages, the angle a, between the outlet 3b and the inlet 5b is equal to- 45/4, i.e., to the angle of rotation of the table from one fixed position to another divided by the number of the outlets of the passages of the column; the angle a between the outlet 3c and the inlet 5d is equal to 2(45l4), while the angle a between the outlet 3d and the inlet if is equal to 3(45/4).

It isquite obvious that the magnitudes of the angles a a, and a are not equal and constitute a progression.

The passages 4 of the stationary column 2 are connected to the pump 6 of the hydraulic system of the machine. The inlets are interconnected by a circular channel 7 with intermediate control valves (not shown). Therefore the process of supplying oil from the inlets 5 of the table 1 to the hydraulic clamping means A is not described herein.

In the process of operation of the machine the oil is fed into the inlets of the table in the following manner:

In each fixed position of the table 1 the oil is forced under pressure by the pump 6 into the passages 4 of the column 2 and through the outlet 3a into-the associated inlet 5a of the table, then through the circular channel 7 to the hydraulic clamping means A (in FIG. 2 there is conventionally shown only one device A; the others are arranged in a similar manner and are connected with the corresponding inlets of the table).

In this case oil is fed into the remaining inlets 5b, 50 through 5h of the table through the annular channel 7.

. As mentioned above, all the inlets 5a, 5b through 5h are symmetrically disposed along the perimeter of the surface of conjugation of the table and column and are filled with oil under pressure. As a result, the forces of the oil pressure between the inlets of the table and the adjacent portion of the conjugated surface of the column acting both on the table and the column are balanced, and this eliminates misalignments and deformations of the table.

The mutual layout of theoutlets of the column and the inlets of the table accomplished according to the invention permits the outlets of the passages to have a small diameter, approximately of 15-20 mm. Therefore, the oil spots formed around these openings have a small area and do not disturb the equilibrium of the forces acting on the table over its surface of conjugation with the column.

This provides for a stable position of the table relative to the column, which, in turn, provides for high accuracy of the workpieces being machined.

The leakage of oil over the surface of conjugation of V the table and column occurs only about said inlets of the table and the outlets of the passages of the column, in which case such a leakage is minimized.

In the process of rotation of the table from one fixed position to another, as indicated by the arrow C, the inlet 5a is displaced from the outlet 3a of the passage, but the effort of the clamping means A is not reduced, because in the process of rotation of the table the oil through the circular channel 7 and the clamping devices A is fed under pressure alternately and successively first into the inlet branch 5b coinciding with the outlet 3b, when the table is turned through an angle oi then into the inlet 5d coinciding with the outlet 3c,

when the table is turned through an angle a and,

thereafter, into the inlet 5f coinciding with the outlet 3d when the table is turned through an angle a When the table is rotated through an angle of 45 into the next fixed position, its regular inlet 5h occupies the place of the previous inlet 5a and coincides with the outlet 34 of the passage of the column. In this fixed position of the table the oil is fed to the circular channel 7 and the clamping means A through the inlet 5h of the table. At each next turn of the table from one fixed position to another the cycle of supply of oil is repeated.

Thus, the leakage of oil over the surface of conjugation of the revolving table and stationary column of the vertical multiple spindle machine is minimized, while providing for a stable position of the table relative to the column and a constant effort on the hydraulic clamping means mounted on the revolving table.

We claim:

1. In a vertical multiple spindle machine having a stationary column with a mounting portion atone end; hydraulic clamping means for fixing workpieces to be machined, an indexible table carrying said hydraulic clamping means, said table being rotatably supported on said column by a central aperture complimentary to said mounting portion of the column; passage means for feeding oil under pressure into said column; said passage means having outlets about the perimeter of said mounting portion of the column; said indexible table having inlets communicating with said hydraulic clamping means; a circular channel formed in said table and communicating with all of the inlets in the table; said outlets of the passage means of said column and said inlets of the table being disposed at the same level and being so arranged that in each fixed position of said table only one of said inlets communicates with one of said outlets of the passage means of said column, said outlets and said inlets being angularly spaced about said column and said table respectively so that during the rotation of said table from one fixed position to another its inlets alternately and successively communicate with the remaining outlets of the passage means of the column.

2. In a vertical multiple spindle machine as set forth in claim 1, in which said inlets of the table are disposed at equal angles about .the perimeter of a table surface contiguous with the mounting portion of the column, and said outlets of the passage means are spaced at unequal angles so that during the coincidence of the only one of said outlets of said passage means of the column with one of the inlets of the table, the outlets of the remaining passage means are displaced angularly relative to the adjacent inlets.

t :u is a 

1. In a vertical multiple spindle machine having a stationary column with a mounting portion at one end; hydraulic clamping means for fixing workpieces to be machined, an indexible table carrying said hydraulic clamping means, said table being rotatably supported on said column by a central aperture complimentary to said mounting portion of the column; passage means for feeding oil under pressure into said column; said passage means having outlets about the perimeter of said mounting portion of the column; said indexible table having inlets communicating with said hydraulic clamping means; A circular channel formed in said table and communicating with all of the inlets in the table; said outlets of the passage means of said column and said inlets of the table being disposed at the same level and being so arranged that in each fixed position of said table only one of said inlets communicates with one of said outlets of the passage means of said column, said outlets and said inlets being angularly spaced about said column and said table respectively so that during the rotation of said table from one fixed position to another its inlets alternately and successively communicate with the remaining outlets of the passage means of the column.
 2. In a vertical multiple spindle machine as set forth in claim 1, in which said inlets of the table are disposed at equal angles about the perimeter of a table surface contiguous with the mounting portion of the column, and said outlets of the passage means are spaced at unequal angles so that during the coincidence of the only one of said outlets of said passage means of the column with one of the inlets of the table, the outlets of the remaining passage means are displaced angularly relative to the adjacent inlets. 